Film developing apparatus



Dec. 31, 1968 w. o. NIX

FILM DEVELOPING APPARATUS Filed Aug. 5, 19

INVENTOR.

United States Patent 3,418,911 FILM DEVELOPING APPARATUS William Otto Nix, Newport Beach, Calif., assignor to Philco Corporation, Philadelphia, Pa., a corporation of Delaware Filed Aug. 3, 1966, Ser. No. 569,895 13 Claims. (Cl. 9589) ABSTRACT OF THE DISCLOSURE A self contained apparatus for developing photographic film includes a developing chamber for receiving film to be processed. The developing chamber has its lower region in fluid flow communication with a fluid supply chamber that has a relatively enlarged, closed upper region into which extend a plurality of valve-controlled discharge nozzles for film processing fluid. Each nozzle is arranged to direct a processing fluid into the supply chamber for flow therefrom into the processing chamber. Valve means is provided for draining fluid from the chambers simultaneously. The enlarged upper region provides for formation of a captive air region that prevents cross-contamination of the nozzles by the different processing fluids. The invention herein described was made in the course of or under a contract, or subcontract thereunder, with the Department of the Army.

This invention has to do with film developing apparatus, and more particularly to self-contained developing chambers for photographic films. While of broader applicability, the invention has particular utility in the developing of dental X-ray films of the kind known as chips.

In certain known apparatus for developing films, valve controlled inlet lines for the several developing fluids lead directly into the developing chamber. Frequently, after valve closure, drops of dissimilar fluids remain suspended from the inlet tubes of such apparatus with resultant risk of cross-contamination upon successive introductions of such fluids.

It is an objective of the present invention to achieve isolation of the different fluids by directing them from individual inlet ports through fluid circuit means so constructed and arranged as to overcome effects of residual drops formed at the inlet ports.

It is a further objective of the invention to provide a substantially self contained film developing apparatus that is readily adaptable for use in automatic film processing means.

In achievement of these objectives, a preferred embodiment of the invention includes, in film developing apparatus, a generally vertically extending developing chamber disposed and adapted to receive a film to be developed and to hold processing fluid for such film. A fluid supply chamber is also disposed to extend generally vertically and has its lower portion in fluid flow communication with a lower portion of the developing chamber. The supply chamber has a relatively enlarged upper portion, and fluid supply means is provided which includes a plurality of fluid discharge nozzle means that extend into the enlarged portion. Each nozzle means is positioned and adapted, to direct a processing fluid into the supply chamber for flow therefrom into the developing chamber, and valve means is provided for draining fluid from the sup ly and the developing chambers simultaneously.

In especial accordance with the invention, the enlarged portion functions as a captive air region, similar in principle to a diving bell, to serve as an isolation chamber for the fluid inlet tubes positioned to direct the several processing fluids into the film processing chamber. By

this construction and arrangement intermixing of fluids is prevented, as is explained hereinafter.

For a better understanding of the invention, and of the best means known to me for achieving the objectives and advantages thereof, reference is made to the following description taken in light of the accompanying drawing in which:

FIGURE 1 is a perspective showing of apparatus adapted for the processing of photographic film according to the invention;

FIGURE 2 is a top plan view of the apparatus illustrated in FIGURE 1;

FIGURE 3 is a bottom view of the apparatus illustrated in the preceding figures;

FIGURE 4 is a sectional view of apparatus as seen looking in the direction of arrows 4-4 applied to FIGURE 2;

FIGURE 5 is a perspective showing of a portion of the apparatus; and

FIGURE 6 is a sectional view of a modified embodiment of the invention.

With more detailed reference to the drawing, and first to FIGURES 1 to 4, apparatus 10 embodying the invention comprises a main body portion 11 provided with inlet conduits 12, 13, and 14 each in fluid flow communication with an air cavity 15 (FIGURE 4). As is best seen in FIGURE 4, the lower end of air cavity 15 is disposed in fluid flow communication with the lower region of a vertically extending developing chamber 16 having at its lower end a drain opening 28 closed by a movable valve plate 17. A manually operable lever 21 engages tabs 29 provided on valve plate 17 at each end, and the plate is resiliently urged to closed position through the agency of a compression spring 22 (FIGURE 4) provided in a recessed portion 24 of the main body portion 11, and reacting between valve plate 17 and a plate 25 spanning a part of recessed portion 24. By this construction the lever .21 also is resiliently urged to its upper position. A sealing strip 18 is provided on valve plate 17 and affords fluid tight engagement of the plate 17 with the body portion 11, to seal drain opening 28.

As is best seen in FIGURES l and 2, the upper portion of developing chamber 16 is provided with an oversized opening 16a that extends beyond the sides of the chamber. A pair of tubes 19 extend downwardly from opening 16a, through the body portion, and into the recessed portion 24. The lower ends of tubes 19 extend through openings 20 in plate 17 (FIGURE 3), thereby serving both as guides for the plate as well as drain means for fluid overflowing from the chamber 16, in the event this chamber is inadvertently over-filled.

Lever 21 is comprised of a generally U-shaped member, as is best seen in FIGURES 2 and 3. Leg portions of the lever are pivotally connected to pins 26, and its loop portion comprises a manual operating flange 27.

It will be appreciated that cavity 15 and chamber 16 communicating therewith comprise a U-tube fluid system. Accordingly, fluid introduced into apparatus 10 will flow downwardly through cavity 15, through the interconnection between the latter and chamber 16, thence upwardly into developing chamber 16. Conduits 12, 13, and 14 are valve controlled, so that by closing valves 12a, 13a, and 14a for each of the conduits (FIGURE 1), cavity 15 is rendered air tight. By this arrangement, the column of fluid in chamber 11 is balanced by the column of fluid in cavity 15 plus the pocket of air entrapped therein. The cavity portion confining the pocket of air is of such configuration as to prevent the fluid from extending up to and immersing the vertically extending nozzle portions of inlet tubes 12, 13, and 14. In this way it is possible to avoid contact with any residual fluid adhering to a pre viously used nozzle. One such nozzle portion appears in FIGURE 4, and is designated by the reference numeral 13b. The latter portions of the tubes are terminated angularly with respect to their axes so as to lessen the possibility of fluid droplets being retained in the nozzle portions. Conveniently, the nozzle portions comprise vertical tubes closed toward their upper ends, as seen at 30 in FIGURE 4.

In operation of apparatus 10, an exposed film 31 is first placed in developing chamber 1 6 devoid of fluid. A first fluid, for example a photographic developing fluid, is then introduced into the inlet conduit :12 into the air cavity 15, and thence into the developing chamber 16. Means (not shown) for metering the fluid, in combination with suitable check valve means, may also be disposed in fluid flow communication with each of the conduits 12, 13 and 14 and their respective control valves 12a, 13a, and 14a. When fluid has sufliciently filled developing chamber 16, as shown in FIGURE 4, air is entrapped within air cavity 15, achieves isolation of the fluid in chamber 16 in relationship to any fluid remaining in the nozzle :portion of inlet conduit 12. It will be understood that a slight rise or fall in fluid level may occur in developing chamber 16, until equilibrium has been reached. Equilibrium is achieved when the atmospheric pressure acting on the exposed surface of the fluid column in chamber :16, in combination with the Weight of the latter, balances the fluid column and entrapped air in the cavity 15.

Valve plate 17 normally is held in sealing contact by the spring 22. To release the fluid after developing has been achieved, the lever 21 is pivoted downwardly, moving valve plate 17, against the urging of spring 22, to open position. Lever 21 is held in a downwardly pivoted position until the fluid charge has drained from both chamber 16 and cavity 15. After the fluid charge has drained, lever 21 is released, and spring 22 returns valve plate 17 to its sealing position. Movement of plate 17 is substantially frontal with respect to the opening 20, and therefore is quickly opened and closed. It will be understood that other, and if desired automatic, means may be provided to actuate the valve 17,. and that such means is within the scope of this invention in its broader aspect. In this connection reference may be had to the embodiment of FIGURE 6.

A second fluid, for example a photographic fixing fluid, is then injected into developing chamber 16 from inlet conduit 13, in the same manner as was the developing fluid, by opening, then closing, valve 13a. After the fixing fluid has acted on the film, it is permitted to drain from chambers and 16.

Water for washing the film is then introduced by way of the third inlet conduit 14 for flow into chambers 15 and 16, by opening, then closing valve 14a. The water is thereafter released to drain from the chambers by operating the lever 21 as described previously.

By virtue of the above-described novel arrangement of the inlet conduits and air cavity, there is no intermixing of the fluid in use in chamber 16 with previously used fluid. In view of the absence of intermixing, the several fluids could, to advantage, be made to return to their original containers by suitable valve means (not shown). In this manner, economical use of the developing, the fix, and the wash fluids could be achieved. It will be further understood that provision can be made for supplying more than the three fluids disclosed, and that water could be introduced more than once to improve the washing action on the developed film. Upon completion of the developing process, the film may be removed and dried by exposure to warm air.

Additional objectives and advantages of the invention will be more fully appreciated from a consideration of the modified embodiment illustrated in FIGURE 6, and particularly adapted for utilization in automatic film processing apparatus of the type disclosed and claimed in the copending patent application of Paul M. Brown et 4 al., Ser. No. 566,941, filed July 21, 1966, and assigned to the .assignee of the present invention.

In the modified embodiment, apparatus 40 comprises a chamber and valve assembly provided with a valve block 49 sandwiched between two plates 42 and 43 interconnected by tie rods (not shown) extending through the valve block 49. Three separate but identical valve systems are provided within the valve block to meter gravitational flow of each of the processing fluids to the developing chamber from a like number of storage tanks, one of which is seen at 44. Inasmuch as construction of each valve system is identical only one is illustrated. Each valve system includes a shuttle spool 47 mounted within a metering chamber 48 formed within valve block 49. A pair of ring type seals 53 are mounted on spool 47 and are positioned and arranged to seal against generally conical surfaces disposed in the upper and lower portions of metering chamber 48. The seal is established, selectively, depending upon the position of the spool.

Valve spool 47 is normally held in its lower position by means of compression spring 54 reacting between an outer portion of the valve block and a washer 55 provided on the spool. In this normally held position of spool 47, fluid may enter metering chamber 48 through holes 56 in the top valve plate 42. Air is vented through tube 57 above the surface of the fluid in the associated tank 44. Metering chamber 48 is filled, and vent tube 57 is filled to the level of fluid in the tank. Fluid is prevented from flowing from metering chamber 48 by sealing engagement of the lower one of sealing rings 53 with the conical surface formed in the metering chamber.

A push-type solenoid 58 is energizable to force valve spool 47 upwardly by means of a vertically reciprocable armature pin 59 abuttingly engaging the valve spol stem. The upper one of sealing rings 53 on valve spool 47 then seals against the upper conical surface in the metering chamber, closing ofl holes 56 in valve plate 42 and preventing fluid from entering metering chamber 48 from the tank assembly.

As the lower one of sealing rings 53 is raised, the lower region of the metering chamber 48 is opened, fluid flows outwardly through the passage 63, the nozzle 64, into the air lock 65, thence into the chamber 66 where the fluid level is raised to cover the film. Solenoid 58 need be energized only long enough for chamber 66 to fill, and when the solenoid is deenergized, valve spool 47 is returned by spring 54 to its lower position, sealing off passage 63 and opening holes 56 in plate 42 so that metering chamber 48 may again fill in preparation for the next cycle. A sealing ring 67 is provided to prevent leakage of fluid past the valve stem.

When valve spool 47 is in its upper position, flow of fluid from metering chamber 48 is halted when the head of fluid developed in processing chamber 66 becomes equal to the head of fluid and air remaining in metering chamber 48, in passage 63 and chamber 65. This arrangement ensures metering of an amount of fluid into processing chamber 66 suflicient only to cover the film.

The cross-sectional area of nozzle 64 is of such small dimension that when valve spool 47 is returned to its lower sealing position, fluid will remain in passage 63. If the nozzle area were too large, for example larger than inch in diameter, there would be a tendency for an air bubble to flow up passage 63 and cause fluid to flow from nozzle 64. The diameter of nozzle 64 preferably is approximately inch, and is sufliciently small to prevent entrance of an air bubble as hereinabove described. Of course, exact diameters depend, in general, on such factors as fluid viscosity, the degree of wetting, types of surface finishes, and the like.

In accordance with the principles of this invention, the air lock chamber 65 isolates incoming fluids from one another as they enter processing chamber 66, by preventing intermingling of fluid in the chamber 66 with the fluids in inlet nozzles 64.

Variations in the amount of fluid available to drain from metering chamber 48, due to fluid contained in vent tube 57 and varying in correspondence to the level of fluid in a corresponding tank, has an insignificant effect on the heads of fluid, because the volume of the tube is too small to change both fluid levels appreciably.

A solenoid operated door 68 is provided across a drain opening 69 in the bottom of processing chamber 66, and is movable away from the opening to dump spent fluids rapidly into a subchamber 70. From subchamber 70, the spent fluids flow through tube 73 into a sealed sump tank 74. An elongated orifice 71 is provided for venting chamber 66 via subchamber 70 and vent passage 72, inasmuch as the top of the processing chamber 66 is sealed by a film holder when the film is inserted therein.

From the foregoing, it Will be appreciated that the invention affords improved, self contained apparatus for processing photographic film, such for example as exposed dental X-ray film. The apparatus is particularly characterized by its capability for maintaining substantial isolation of the several processing fluids as they are introduced into the processing chamber. Moreover, the apparatus is readily adaptable to incorporation in automatically 0perable film handling apparatus, as will be appreciated from a consideration of the referenced copending disclosure. The foregoing as will other advantages Will be still further appreciated from a consideration of the appended claims.

I claim:

1. In film developing apparatus: a developing chamber disposed and adapted to receive a film to be developed and to hold processing fluid for such film; a fluid supply chamber substantially at the level of said developing chamber having its lower region in fluid flow communication with a lower region of said developing chamber, said supply chamber including a relatively enlarged upper region; fluid supply means including a plurality of fluid discharge nozzle means extending into an upper portion of said enlarged upper region, each said nozzle means being operable, selectively, to direct a processing fluid into said supply chamber for flow therefrom into said developing chamber, and terminating at a level disposed above the normal fluid level in said supply chamber but at a level below the corresponding normal fluid level in said developing chamber; and valve means for draining fluid from said chambers simultaneously.

2. Apparatus according to claim 1, and characterized in that said valve means comprises a drain opening in fluid flow communication with the lower ends of said supply and said developing chambers, and a closure plate for said drain opening movable toward and away from the latter, selectively to open or to seal said opening.

3. Apparatus according to claim 2 and further characterized in that said closure plate normally is resiliently urged to closed position, and by the inclusion of lever means operable to move said plate sub-stantially frontally away from said drain opening.

4. Apparatus according to claim 2 and further characterized by the inclusion of linkage means operable to move said closure plate substantially frontally with respect to said drain opening.

5. Apparatus according to claim 1, and characterized in that each said nozzle means terminates in an opening disposed in angular relationship to the axis of each nozzle means.

6. Apparatus according to claim 1, and characterized in that each said supply chamber and said developing chamber extends substantially vertically.

7. Apparatus according to claim 1, and characterized further by the inclusion of overflow drain means disposed in fluid flow communication with an upper region of said developing chamber.

3. Apparatus according to claim 1, and further characterized by the inclusion of a plurality of fluid supply valve means, each in fluid flow communication with a nozzle means, and operable sequentially to feed a different processing fluid to said supply chamber.

9. Apparatus according to claim 8, and further characterized in that each said supply valve means comprises a valve chamber having an inlet port communicating with fluid supply means and an outlet port communicating with said supply chamber, and a reciprocably movable valve spool movable to a first position closing said outlet .port and opening said inlet port whereby to fill said valve chamber with a processing fluid, and movable to a second position opening said outlet port and closing said inlet port, whereby to empty said valve chamber into said supply chamber.

16'. Apparatus according to claim 7, and characterized in that said overflow drain means comprises a pair of substantially parallel tubular members, and said valve means comprises a valve plate slidable on said members to and from a chamber sealing position.

11. In fluid treating apparatus: an upwardly extending treating chamber for receiving an article to be treated and for holding a predetermined quantity of fluid for treating such article; fluid supply means for said chamber, including a plurality of individually controlled fluid discharge nozzle means positioned and operable to supply different fluids for said chamber; and means for preventing intermingling of the different fluids as they are individually supplied, said means comprising an upwardly extending fluid passage within which the fluids are received from said nozzle means and having its lower region in fluid flow communication with the lower region of said treating chamber, and an air lock chamber interposed intermediate said fluid passage and said nozzle means at substantially the level of said chamber, said air lock chamber being effective to entrap a quantity of air sufficient to establish and maintain a normal fluid level therein below the level of said nozzle means, upon introduction of the recited predetermined quantity of fluid into said treating chamber.

12. Apparatus according to claim 11, and further characterized by the inclusion of valve means operable to drain fluid from said treating chamber and said fluid passage simultaneously.

13. Apparatus according to claim 12, and characterized further in that said valve means comprises a drain opening in fluid flow communication with said lower regions of said treating chamber and said fluid passage, and a closure plate for said drain opening mounted for movement toward and away from the latter, selectively to open or to seal said opening.

References Cited UNITED STATES PATENTS 3,280,716 10/1966 Gall -89 3,345,929 10/1967 Oksakovsky et al. 95-96 NORTON ANSHER, Primary Examiner. C. E. SMITH, Assistant Examiner.

US. Cl. X.R. 

